I've recorded performance with several counters, but I would like to display only one of these at a time.
Even when I uncheck the boxes from the "Chart counters" zone in the upper left, the counters are still displayed in the graph.

I am able to reproduce this problem on one of my machines--kindly bear with me as I look into this!

Regarding the gigantic processor time..

Out of range values like this can happen sometimes because of glitches in Microsoft's implementation of performance counters (ANTS reports the same values as perfmon would). The out of range values are more likely to occur if the counters are read too frequently or at times of high system load. (The same effect will be visible in perfmon, but it's not as noticeable as perfmon overwrites previous data after a minute.)

There's not a lot that ANTS can do about this, I'm so sorry to say, as it is a problem with the Microsoft counters. :/

Because I also removed the multi-targeting pack (now I know it's part of Visual Studio 2010), I also had to uninstall Visual Studio 2010 SP1, repair Visual Studio 2010 and then reinstall Visual Studio 2010 SP1.

This took a lot of time, but doesn't change anything concerning the timelilne problem.

So sorry to hear that hasn't helped! I did some more testing and it seems that the unchecking feature may actually require that .NET 4.5 is installed. We have a bug logged for this with reference PP-30230 and are still investigating. Please bear with us--I will post here once there is an update!

In the meantime, the feature will likely work if you save your results and view them on a machine where .NET 4.5 is installed (but please let us know should that still fail for you!). So sorry for the inconvenience this bug causes!

I wasn't sure if you'd want to install .NET 4.5 on your machine, but you hopefully shouldn't experience any issues and need to uninstall. If so, just viewing the results on a machine with it already installed should work.